Lying in a Mexican hospital with screws supporting his fractured spine, Larry Smith can't believe how close he came to dying and why his friend, Elgin Barron, did.

Barron was among five Canadian tourists killed Sunday when an explosion ripped apart a section of the Grand Riviera Princess Hotel. Two Mexican staff workers were also killed.

Smith was just steps away from where the explosion occurred and was thrown to the ground.

"I do remember hitting the floor. I do remember debris hitting me. I do remember being hit in the back," he told CTV News.

"I could just see the devastation. And my buddy was there. It was just terrible. Terrible."

Smith was getting a morning coffee for his wife, Linda, when the blast occurred.

She was in her room and scrambled to find out what happened.

"It was chaos. People were running around and I went to the building where my husband was in and it was just about gone," Linda Smith said. "I basically just walked around wondering if he was alive. And nobody knew."

The Smiths' daughter, Julie, says the thought of losing her father is too much to bear.

"When I go to sleep I just keep on thinking my dad was in an explosion. But it's like hitting a brick wall. You can't feel anything," she said.

Authorities still don't know what caused the explosion, and may not know for months.

They first blamed a buildup of underground swamp gas, but a government environment agency later ruled that out.

Officials are looking into other explanation, including whether the explosion was caused by a buildup of methane gas in a sewage line.

Larry Smith's doctors believe he may be well enough to fly back to Canada next week.

With a report from CTV News' Omar Sachedina